Spin-waves, i.e. propagating perturbations in the arrangement of spins in magnetic materials, are envisioned to revolutionise the way information is carried and processed due to their multiplexing capability and absence of Joule losses.[1],[2],[3] The control of the propagation and the detection of spin-waves are the basis for developing the building blocks of future magnonic devices, such as spin-wave waveguides and spin-wave interferometers. In this framework, recently it was proposed that spin-wave logic gates based on Mach-Zehnder type interferometer could allow for universal logic functions.[4]

 

Conventionally, the engineering of spin-waves is achieved via physically patterning magnetic nanostructures such as magnonic crystals, and magnetic micro-nanowires.2 The control of spin-waves in such structures led to the demonstration of a plethora of magnonic devices,[5],[6] however fundamental limitations are still to be overcome before magnonics becomes an appealing alternative to CMOS electronics. In particular, efficient ways for guiding and propagating spin-waves in nanostructured materials are still missing. [6],[7] Recently, we demonstrated the nanopatterning of reconfigurable magnetic domains in an exchange biased continuous ferromagnetic layer, by sweeping the heated tip of an atomic force microscope (AFM) onto the film surface (thermally assisted magnetic scanning probe lithography, tam-SPL).[8] This technique is straightforward and combines the reversibility and stability of exchange bias, as the same pattern can be written and reset, with the resolution of scanning probe lithography. This allows for the development of novel metamaterials with finely tuned magnetic properties, as well as reconfigurable computing device architectures. Preliminary results on the control of spin-waves within domains patterned via tam-SPL were also demonstrated, paving the way towards the use of tam-SPL for engineering magnonic functionality.

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The aim of this research project is to enable major advances in the field of magnonics by nanopatterning magnonic logic devices via tam-SPL in continuous films. In such devices, spin-waves will be efficiently guided and manipulated by defining topological features, such as magnetic domains and domain walls, avoiding any detrimental magnon scattering at physical interfaces. Furthermore, devices patterned via tam-SPL will be fully reconfigurable, allowing for the on-demand change of their functionality.

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​‘SWING’ project brings together a wide range of techniques and competences belonging to magnetism and nanoscience.

We aims to push magnonics forward by proposing innovative solutions for efficiently guiding and manipulating of spin-waves in nanostructured materials, bringing closer the envisioned revolution of magnon-based computing.

 

[1] The next wave. (2015). Nature Physics, 11(6), 437–437.

[2] Neusser, S., & Grundler, D. (2009). Advanced Materials, 21, 2927–2932.

[3] Csaba, G., Papp, a., & Porod, W. (2014). Journal of Applied Physics, 115, 17C741.

[4] Lee, K. S., & Kim, S. K. (2008). Journal of Applied Physics, 104(2008), 10–14.

[5] Chumak, A. V, Serga, A. a, & Hillebrands, B. (2014). Nature Communications, 5, 4700.

[6] Vogt, K., Fradin, F. Y., Pearson, J. E., et al. (2014). Nature Communications, 5, 3727.

[7] Neusser, S., Duerr, G., Bauer, et al. (2010). Physical Review Letters, 105(6), 067208.

[8] Albisetti, E., Petti, D., Pancaldi, M., Madami, M., Tacchi, S., Curtis, J., King, W.P., Papp, A., Csaba, G., Porod, W., Vavassori, P., Riedo, E. & Bertacco, R.. Nanopatterning reconfigurable magnetic landscapes via thermally assisted scanning probe lithography. Nature Nanotechnology, 11, 545–551 (2016)